Routers have become a popular tool in woodworking due to the flexibility of the tool allowing it to carry out a number of different functions. This flexibility has been particularly enhanced by providing a router table with an upper surface on which the workpiece can be located and moved so as to move relative to the fixed router and the router bit which projects through the surface.
Routers therefore are commonly used with a router table and in many cases the router table includes an insert plate which is bolted onto the end plate of the router so that the drive shaft of the router projects through an opening in the plate to the router bit which is presented wholly or partly above the surface to act upon the workpiece. Different arrangements of bits can be used for different functions.
In some cases the router is used to cut a groove in the under surface of the workpiece with the groove being shaped in dependence upon the shape of the bit for various different arrangements and uses.
In other functions, the bit is used to cut or shape an edge of the workpiece. In this case the workpiece can be guided by a fence mounted on the table at the bit. Other arrangements of guide fence are well known to one skilled in the art for co-operation with various guide elements which can be attached to the workpiece or to the table.
Routers can also be used as hand held or manual tools where the workpiece is clamped to the table and the router bit moved over the workpiece. The bit axis is maintained at right angles to the workpiece surface by providing a router end plate lying in a radial plane of the bit so that the bottom surface of the end plate can slide over the workpiece in contact with the upper surface thereof.
One problem area which remains in such routers, despite many years of development and availability, is that of removing the machined waste material in the form of dust or chips which can be expelled into the air or left as waste material on the table or on the workpiece.
This problem has been sufficiently severe to limit the desirability of this machining method since the material expelled into the air is difficult to control and can be at best unpleasant and at worst environmentally damaging.
Various attempts have therefore been made to extract the dust and particles from the area of the workpiece including overhead suction nozzles which are attached to a suction duct. Such suction nozles can be adjusted and located at a suitable position so as to attempt to carry away the dust and particles expelled by the bit in an upward direction away from the table. This arrangement is unsatisfactory in that it is unable to collect all of the materials escaping into the air and in that it often leaves materials on the table which interfere with the operation and movement of the workpiece, or it leaves materials on the workpiece which interfere with the movement of the hand held router.
Another arrangement has been provided to generate suction around the bit at the bit opening in the table. This is normally provided by generating a suction duct in the end plate of the router. Thus the end plate around the motor is machined with various walls and dividers in the end plate it is clamped to the underside of the table so as to generate a suction around the bit opening to attempt to extract material which is released at the bit into the end plate of the router and from that end plate into a suction nozzle attached to the router itself. This arrangement has become widely and commonly accepted in the router industry and many routers are currently available with such a suction extraction system. However the system has been revealed to be less than satisfactory leaving many particles on the table and still allowing dust to expel into the air.
Up until now there has been no simple solution to problem of waste material extraction and this remains and has remained a long standing problem.